I just received my PH100 today, and it sounds like my AKG K242HD's will be spared the auction block. It's nice to hear that they do actually have some weight to them in the bottom of the spectrum.
I've been powering them with a little dot 1+. This amp apparently doesn't have the power capability the AKG's require. The amp sounded fine with a set of Shure 840's (they went back to the guitar center) I had for a couple weeks. The 840's sound fine, but are very heavy and I have weird ear pressure issues with completley sealed phones. Anyway, after my 242HD arrived I was pleased with the sound except for a nearly complete lack of bottom end response. I chalked it up to a lack of burn-in time. Fast forward about 150 hours, and the 242's have marginally better bottom end response, but still not acceptable to me. They were about to be sold. I've read several times that the AKG 70x series require a lot of power to sound their best and figured that this could be the case with my 242HD. Plus, what a great excuse to add another amp to the collection!
Now, with the three hours time I've got on the amp so far, I've got a different set of 242HD on my head. They've got weight, extension, and transient attack that wasn't there before. I'm much happier so far. There is just a tiny touch of sibilance/edginess that I'm hoping will smooth out with time. I'll post an update, but this amp is a great buy in my book!